Multicell cuvette package, method of loading multicell cuvettes into a measurement instrument and a dispensing device for loading cuvettes

ABSTRACT

A cuvette package for loading multicell cuvettes from a package into measurement instruments having their cuvette loading accessories designed to accept known packages. On top of a row of multicell cuvettes is attached a detachable bonding strip having a width smaller than that of the width of the row of multicell cuvettes. The bonding strip serving to keep the row of cuvettes together during transport and being easily detachable when the cuvettes are being loaded into the instrument. The multicell cuvettes are loaded into the instrument from the dispensing device which supports the cuvette package in place and has its top surface provided with an opening permitting the removal of the strip by pulling off from the supported multicell cuvette package.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cuvette package, a method of loadingmulticell cuvettes packaged in such a package into a measurementinstrument and a dispensing device for loading multicell cuvettes fromsaid package according to the invention into measurement instrumentshaving their cuvette dispensing means designed for packages that havebeen used earlier.

2. Description of the Related Art

For the assay of different liquids, analytic laboratories employautomatic analyzers in which the liquids to be assayed are placed inreaction vessels, designed to perform simultaneously as cuvettes of highoptical quality. Generally, a row of reaction vessels or single-cellcuvettes may be combined into a multicell module of reaction vessels,separated from each other by a vertical wall and cast into asingle-piece row. Herein, the reaction vessels are adapted side-by-sideinto an integral module with a common wall separating any two adjacentvessels and the long vertical sides of the multicell cuvettes madestraight so that the multicell cuvettes in turn can be placedside-by-side into a contiguous row in which the long sides of thecuvettes are tightly adjacent to each other. Thus, the cuvettes can bestored in a rectangular container during transport and other handling.Such a multicell cuvette design is disclosed in U.S. Pat. No. 4,690,900.Cuvettes of the above-described type are easy to handle and givereliable measurement results.

In use, cuvettes must be kept free from dust, scratches and breakage sothat the radiation passed in the analyzing instrument via thetransmissive window surfaces of the reaction vessels would give reliableassay results. Hence, cuvettes must be treated with great careimmediately after their manufacture in the subsequent packaging,storage, transport and measurement steps.

In the practical use of such cuvettes, a need has arisen for such apackaging method of cuvettes that can keep the cuvettes absolutely freefrom dust, scratches and fingerprint stains. While the packaging stepensuing the injection-moulding of the cuvettes can be performed fullycontrolled by automation methods and means, impact blows and humanmishandling of the cuvette packages themselves during the loading of thecuvettes into the analyzing instrument have caused problems. To minimizesuch drawbacks, a cuvette packaging method has been developed in whichthe cuvettes are packaged into a row placed in a covered box with aremovable cover. The mouth part of the package is shaped to fit into thecuvette intake port of the instrument, and the push lid of the packageis provided with a pusher element for loading the cuvettes intoinstrument. When the package is attached to the cuvette intake port ofthe instrument, the cuvettes are transferred into the instrument by wayof pushing the row of multicell cuvettes from behind with the help ofthe detachable push lid of the package, said lid incorporating aseparate pusher element, which forms the other end of the package whenthe lid is still attached to the package. The benefits of this packagingmethod include dust-free handling, freedom from fingerprintcontamination on the optical window areas of the cuvette or scratches ofthe same due to manual handling.

Such a box package has, however, some drawbacks which deteriorate itshandling properties and increase packaging costs. The manufacture of thepackaging box is costly in regard to the cost of cuvettes, whereby theunit price of assays will be increased by the expensive package. Thediscarded packages leave a great amount of plastic scrap to betransported to a dump or plastic materials recycling site. As theconsumption of cuvettes in many laboratories has a high volume and thematerial of the packaging box may be different from the other plasticscrap resulting from the operation of the laboratory, this conventionalarrangement is inferior in terms of recycling. Furthermore, the sortingand storage of cuvette packages in the laboratory spaces is clumsy.Since cuvettes are disposables and thus should not be recycled but asmaterial, the cuvette package should contain the absolute minimum ofmaterial and the packaging materials should be easy to collect andrecycle. While cuvettes in principle could be washed and reused, theiroptical window surfaces are extremely sensitive to contamination andmechanical damage. Therefore, cuvette manufacturers advise against reuseof cuvettes, because the risk of erroneous measurement results due todamaged/soiled cuvettes is high in the reuse of cuvettes.

Due to lower cost and material minimization, the cuvette packaging boxmust be made from thin material, whereby its rigidity is impaired.Resultingly, the box is readily warped and distorted as well as clumsyto use; the box and the cuvettes therein tilt easily, the cuvettestopple during their loading into the instrument and the box mouth cannotbe held positively mounted on the cuvette intake port of the instrument.When fallen or tilted cuvettes are guided or erected manually, they areeasily damaged by fingerprints or even scratches, which may causeerroneous measurement results. One problem hampering conventionalpackages is that the intake capacity of cuvette loading bays variesbetween different instrument makes, whereby also a varying number ofexcess cuvettes will always remain in the cuvette packages, andresultingly, the next batch of cuvettes must be loaded from two boxes insuccession, whereby the number of incorrectly loaded cuvettes obviouslywill be higher.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a cuvette packageand a compatible method of loading multicell cuvettes from such apackage into an instrument, said package and method offering essentiallyreduced material consumption in the manufacture of the package, a lowerrate of errors in cuvette loading and more effective elimination ofinadvertent damage to cuvettes.

The goal of the invention is achieved by attaching on top of a row ofmulticell cuvettes such a detachable bonding strip of a width smallerthan that of the width of the multicell cuvettes, said bonding stripserving to keep the row of cuvettes together during transport and to beeasily detachable when the cuvettes are being loaded into theinstrument.

According to the invention, the cuvettes are bonded into a package withthe help of a single strip of self-adhesive tape or similar band whoseunderside can be attached to the tops of cuvettes placed in rows.Besides the cuvettes, the package thereby contains no other parts ormaterials except the easily disposable strip of self-adhesive tape.Resultingly, the amount of packaging material to be discarded remainsminimal. The strip protects the reaction spaces of the cuvettes veryefficiently from dust and debris even up to the most distal cuvettes inthe row. The rear end of the strip is folded over the optical windowarea of the last cuvette in the row so as to form a handling shield thuspermitting manual pushing of the row of cuvettes from the rear side ofthe row, whereby the optical window surfaces of the last multicellcuvette in the row need not be touched by fingers at any moment. Thenumber of cuvettes in a package and the dimensions of the cuvettedispensing device of the measurement instrument are standardized,whereby each package contains a row of 25 multicell cuvettes, which canbe loaded as a batch into the instrument. This arrangement avoids thestoring of half-empty packages.

The novel package according to the invention is cheaper than aconventional box package and produces less plastic scrap. The cuvettesare easier to load from the package according to the invention into ameasurement instrument of suitably designed construction, and when theloading operation is performed using the full cuvette batch of the novelpackage, there is no need nor opportunity offered for handling cuvettesindividually. This arrangement assures maximum hygienic and opticalcleanliness of cuvettes and prevents mechanical damage thereto. Ascontamination and marring of cuvettes can essentially impair thereliability of measurement results, cleanliness and intact condition ofcuvettes is crucially important for reliable function of measurementinstruments.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be examined in greater detail withthe help of the appended drawings in which are given by way ofillustration only, and thus are not limitative of the present invention,and wherein:

FIG. 1 shows a side view of an embodiment of the cuvette packageaccording to the invention;

FIG. 2 shows a top view of an embodiment of the cuvette packageaccording to the invention;

FIG. 3 shows an embodiment of the cuvette package according to theinvention viewed from the end of the package to be attached to themeasurement instrument;

FIG. 4 shows an embodiment of the cuvette package according to theinvention viewed from the end of the package protected by the bondingstrip;

FIG. 5 shows a side view of an embodiment of the cuvette dispensingdevice with the cuvette package placed therein;

FIG. 6 shows a top view of an embodiment of the cuvette dispensingdevice with the cuvette package placed therein;

FIG. 7 shows an embodiment of the cuvette dispensing device with thecuvette package placed therein as viewed from the direction of thecuvette intake port of the measurement instrument;

FIG. 8 shows a top view of the dust protection cover of a separatecuvette caddy box;

FIG. 9 shows a top view of the discharge end cover of the separatecuvette caddy box;

FIG. 10 shows a top view of the separate cuvette caddy box;

FIG. 11 shows a side view of the dust protection cover of the separatecuvette caddy box;

FIG. 12 shows a side view of the discharge end cover of the separatecuvette caddy box;

FIG. 13 shows a side view of the separate cuvette caddy box; and

FIG. 14 shows the separate cuvette caddy box with the cuvettes thereinas viewed from the direction of the cuvette intake port of themeasurement instrument.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, therein is shown a cuvette package 41 according tothe invention. The package is comprised of a plurality of conventionalmulticell cuvettes 4 of multiple reaction vessels, placed in a row, andof a bonding strip 1 serving to keep the multicell cuvettes together inthe row. Each multicell cuvette 4 has a hook member 25, from which themulticell cuvette 4 can be grasped for transport within the measurementinstrument. The bonding strip 1 is attached to the multicell cuvettes bymeans an adhesive coating 3 placed on the underside of the strip,whereby the strip adheres to the top of the multicell cuvettes at thearea surrounding the mouths of the reaction vessels. The strip 1 may bemade from, e.g., self-adhesive polypropylene tape having its adheringsurface covered with an acryl-based adhesive of good weather andlow/high temperature resistance. The bonding strength must be so highthat, on one hand, the package can be handled by lifting or bending, forinstance, and, on the other hand, the strip can be removed by pullingwith a moderate force. Furthermore, the adhesive coating 3 must benonstaining and of a type that leaves no excessive residues of theadhesive on the rim surfaces of the reaction vessels when removedtherefrom.

The adhesive, which may be formulated from, e.g., an acryl dispersion,is selected to have suitable adhesion and removal force properties. Thecold/hot temperature resistance of the adhesive must be sufficientlygood to avoid inadvertent detachment of the bonding strip duringstorage. Obviously, the adherence strength of the adhesive need to becompatible with the available bonding area, whereby the bonding strengthbetween the bonding strip 1 and the multicell cuvettes 4 can be variedby modifying the surface area used for bonding. The adhesive can beapplied over a narrow area at the strip edges, or in the strip center orover any other suitable area, or obviously, even over the entire widthof the strip.

The leading end of the bonding strip 1 is formed into a pull tab 2 whichis folded over the top of the row of multicell cuvettes for the durationof transport and storage. The pull tab 2 is made sufficiently long for aconvenient grasp with fingers and it is left free from the adhesivecoating. The trailing end of the bonding strip 1 is formed into a skirttab 5, bent over the optical window area 8 of the last cuvette in therow, whereby the skirt tab makes it possible to push the row ofmulticell cuvettes from the rear side of the row without contaminatingthe optical area 8 of the last cuvette in the row. The length of theskirt tab 5 is selected so that overlapping length of the tab isslightly shorter than the height of the cuvette, yet sufficiently longto cover the optical area 8. Thus, the last cuvette in the row can besupported by its lower edge without any interference by the skirt tab 5which gives protection to the optical area 8. The underside of the pulltab 2 and the trailing end skirt tab 5 of the bonding strip are leftfree from the adhesive coating.

The bonding strip 1 is made narrower than the cross-package length ofthe multicell cuvette 4, whereby a gap 7 remains between the outer edgesof the strip 1 and the ends of the multicell cuvette 4. When the packageis being unloaded, the row of multicell cuvettes can be supported fromabove at the edge 9 of the row of the multicell cuvettes. The bondingstrip 1 covers almost perfectly the mouths of the reaction vessel spaces6 formed in the multicell cuvettes, thus protecting the cuvettes fromgathering dust. The mouths of the most peripherally situated reactionvessels may be left marginally covered at the edges. When the cuvettesare being loaded in the measurement instrument, the bonding strip 1 canbe removed—at the same time relieving the cuvettes from the package—bysupporting the package simultaneously at its front edge 11, rear edge10, on top at the free edges 9 and from the direction of the packagebottom 13 and sides 12. When the package is supported in theabove-described manner, it can be unloaded by pulling the bonding stripoff from the top surface of the multicell cuvettes 4, whereby thecuvettes are detached from the adhesive coating 2 of the bonding strip.

The bonding strip 1 can be made from a variety of different materials,and respectively, its detachable bonding can be implemented using aplurality of different methods. Most advantageously, the strip is madefrom an elastic and flexible material such a polypropylene or reinforcedpaper. Preferably, the strip is made maximally wide, whereby it willcover the reaction vessels during transport. Obviously, the strip may bemade very narrow if the protection of the cuvettes is simultaneouslysecured by placing the cuvette packages into larger, dust-prooftransport containers. When a wide bonding strip is used, the adhesivecan be applied to selected areas of the strip only, e.g., as narrowstripes of adhesive at the edges of the strip. In the case that theadhesive is placed on narrow areas only, the adhesive can have a hightacking power if the required easy detachability is simultaneouslyassured by making the area of adherence sufficiently small. When thebonding strip is adhered using ultrasonic welding or heat-sealing, itsattachment can be advantageously accomplished by means of spot-likebonding surfaces, whereby the proper bonding strength may be controlledby altering the number of the bonding spots. The strip may be made froma material of higher stiffness, whereby also the package will becomerigid.

In FIGS. 5-7 is shown a dispensing device particularly suited to serveas an automatic dispensing device for loading multicell cuvettes intomeasurement instruments. Such a cuvette dispensing device has a frame 14containing a gutter-like space suited to accommodate the cuvette package41. The frame is made from an aluminium continuous section. The sides ofthe package space are formed by upright walls 39 terminating at theirupper edges with lips 19 pointed toward the center line of thedispensing device. Both ends of the dispensing device have stops 15 and16 serving to locate the front and rear ends 11, 10 of the cuvettepackage in place. One internal wall 39 of the package space is providedwith an elongated groove-like recess 24 dimensioned to accommodate thehooked end 25 of the multicell cuvettes 4. The bottom of the packagespace has elevated guide rails 20 on which the multicell cuvettes canslide without damage. One or more of these cuvette dispensing devicesmay be used as an automatic loading accessory when connected tomeasurement instruments. If a number of cuvette dispensing devices areused in combination, they can be arranged in different ways movable onguides so as to be sequentially transferrable to coincide with thecuvette intake port of the instrument, or alternatively, the dispensingdevices can be adapted to form a revolver magazine. From the packageaccording to the invention, the cuvettes are loaded into the instrumentby virtue of the above-described dispensing device in the followingmanner.

The cuvette package 41 is placed in the dispensing device by pushing thepackage into the package space via infeed end 17 of the device, wherebythe trailing end skirt tab 5 provides protection for the optical windowsurface of the cuvette against fingerprints. A stop 16 at the infeed end17 is simultaneously pushed receding downward so as to permit freepassage of the cuvette row, while a stop 15 at the outfeed end 18 of thedevice counters the passage of the package stopping it in place, wherebythe infeed end stop 16 can rise up. The lips 19 of the device frame 14give support to the cuvettes from above, while the walls 39 support thepackage from the sides and the guides 20 of the frame bottom providesupport from below. Thus, the cuvettes are supported from all sides intoa fully stabilized position. The strip joining the cuvettes remains inthe free area between the lips 19, wherefrom it can be removed bypulling from the pull tab 2 of the strip 1. Next, the cuvettes can befed forward by opening the outfeed end stop 15 and pushing the lastcuvette from the side closer to the infeed end 17. Advantageously, thecuvettes are pushed with the help of a separate, automatic pusher means,whereby the only task remaining for the instrument user to carry out isthe insertion of a new cuvette package into the cuvette dispensingdevice after the previous cuvette batch is exhausted. The exhaustion ofcuvettes can be signalled by a visual, audible or other suitableindicator means.

In FIGS. 8-14 is illustrated a device suited for the cuvette packageunloading and manual infeed of the multicell cuvettes. FIG. 8 shows atop view of a pusher element serving for manual pushing of cuvettes;FIG. 11 shows the same element in a side view. In FIG. 9 is shown a topview of the cover 26 via which the bonding strip of the cuvette packagecan be removed. FIG. 12 shows the same cover 26 in a side view. In FIG.10 is shown a separate cuvette caddy box 21 into which the cuvettes areplaced during the package unloading step. In FIG. 13 the same caddy boxis shown in a side view and in FIG. 14 in a front view.

The pusher element comprises a push lid 31 and a push edge 32. The pushlid 31 is dimensioned so that it covers the opening of the dispensingdevice cover 26, whereby the lid acts as a dust cover of the dispensingdevice. The push edge 32 is dimensioned so as to permit the movement ofthe push lid in the cuvette storage space of the caddy box 21. Thedispensing device cover 26 has narrow lips 43 dimensioned to mate withthe edges of the internal walls of the caddy box 21. Additionally, thecover 26 is provided with an opening 28 bordered by edges 29. The frontedge of the cover includes a backing lip 27 and a lift edge 44. Theopening 28 of the dispensing device cover is dimensioned wider than thebonding strip 1 joining the row of cuvettes, but narrower than thecross-package width of the row of multicell cuvettes, whereby themulticell cuvettes placed in the caddy box 21 can be supported fromabove by means of the dispensing device cover 26. The caddy box 21itself comprises a bottom 22, side walls 24 and 38 as well as a rear endwall 23. One side wall 38 is upright straight, while the other side wall24 is made slanted at its edge joining with the bottom 22, whereby theupright straight side of the cuvette row can be placed abutting thestraight wall 38 and the hooked end 25 of each multicell cuvette in therow is situated facing the slanted wall 24, where the properlydimensioned slanted side of the wall provides extra space to accommodatethe hooked end 25 of the multicell cuvettes. The mouth part 37 of thecaddy box 21 is dimensioned to match the dimensions of the cuvetteintake port of the instrument.

When the cuvettes are loaded into the instrument by means of theabove-described device, the cuvette package is first placed into thecaddy box 21. The bottom 22 of the caddy box supports the cuvettes frombelow, the rear end wall 23 from behind the last cuvette in the row andthe walls 38 and 24 from the sides. Herein it must be noted that theslanted wall 24 on one side of the caddy box 21 inhibits the cuvettesfrom being placed in the caddy box in any other way but with the hookedend 25 facing the slanted wall. Next, the caddy box is covered with thedispensing device cover 26. The backing lip 27 of the cover supports thecuvettes from the front side. The opening 28 on the cover top is madewider than the cross-package width of the bonding strip joining thecuvette tops, yet narrower than the cross-package length of themulticell cuvettes. Thus, the edges 29 of the opening can support thecuvettes from above. For the duration of the strip removal step, thecover must be locked to the caddy box 21, or alternatively, compressedagainst the caddy box, e.g., manually in the direction of arrow 30 inthe diagram. Thus, the cuvettes will be clamped in place and the stripcan be safely removed via the opening 28 by pulling from the pull tab 2.After the removal of the bonding strip 1, the cuvettes can be loadedinto the instrument by elevating the dispensing device cover 26 andactuating the push lid 31. The push edge 32 at the front end of the pushlid is inserted in the interior of the rear end 23 of the caddy box,behind the last multicell cuvette in the row, and the cuvettes aretransferred out from the box into the measurement instrument in thedirection of arrow 40 in the diagram. The infeed end 37 of the caddy boxis designed to be compatible with the cuvette-handling mechanisms of theinstrument. Also the push lid 31 is dimensioned so that it can cooperatewith said mechanisms of the instrument. The push lid 31 can be used as adust cover by placing it over the opening 28 of the dispensing devicecover so that the lid covers the entire opening and has the push edge 32at its front end located pointing outward from the top of the caddy box.Positive locking of the different elements to each other can be assuredby providing the element with conventional clamping means.

In addition to those described above, the invention may have alternativeembodiments.

As mentioned above, the bonding strip joining the row of multicellcuvettes may be made from different types of materials and with varyingdimensions. Furthermore, the bonding strip may be adhered to thecuvettes using a plurality of different methods. The strip can beprovided with printed information such as operating instructions,manufacturer's name and labelling as well as other informationconcerning the use and recycling of the package. The design of cuvettedispensing devices may be varied widely as to their external form,provided that the device in all of its embodiments provides sufficientspace to accommodate a row of cuvettes and has means for supporting thecuvettes from above during the strip removal step. Alternatively, thecuvettes can be loaded using a conventional cuvette dispensing box ifthe loading system is complemented with a dispensing device cover of thekind shown in FIG. 12 to facilitate the removal of the bonding strip, bymeans of which cover the cuvettes can be supported in the caddy boxduring the strip removal step. The caddy box and the cover can beconnected with each other by a hinge or other suitable means.Furthermore, the dispensing device cover and the push lid can bedesigned into an integral entity, because after the strip is removed,the cuvettes need no more any support from the dispensing device cover.However, then the cover must be provided with a removable or hinged lidvia which the strip can be removed. The cuvette caddy box or cuvetteloading device need not be a box with solid walls, but instead, apartially open structure such as one having walls of a mesh or latticestructure can be used. In addition to different metals, the frame of thecuvette caddy box or cuvette dispensing device can be made fromdifferent types of polymers or composite materials, even prepared intocontinuous sections of varying shapes. While the number of cuvettes inthe package may be varied, the use of standardized package size isobviously the most advantageous choice for both the instrument user andthe cuvette supplier.

What is claimed is:
 1. A handling package of multicell cuvettes, saidpackage comprising: a row of multicell cuvettes formed by a plurality ofreaction vessels, said reaction vessels of the multicell cuvettes beingadapted adjacent to each other so that the vessels have a commonseparating wall, whereby the multicell cuvettes may be packed in acontiguous row in which long sides of abutting multicell cuvettes areplaced tightly adjacent to each other; and a bonding strip adherable toa surface about a mouth of the reaction vessel of the multicell cuvettesso as to be detachable prior to use, said strip serving to join the rowof multicell cuvettes into a contiguous handling package, wherein saidbonding strip has a width smaller than the cross-package length of themulticell cuvettes.
 2. A package as defined in claim 1, wherein saidbonding strip is a flexible band.
 3. A package as defined in claim 2,wherein said bonding strip is attached by ultrasonic welding.
 4. Apackage as defined in claim 1, wherein said bonding strip is adhered bymeans of a bonding medium having adhesive properties.
 5. A package asdefined in claim 1, wherein a bonding medium is applied to cover thewidth of said bonding strip only partially.
 6. A package as defined inclaim 1, wherein said bonding strip is attached by ultrasonic welding.7. A package as defined in claim 6, wherein said bonding strip isattached by spot-welding.
 8. A package as defined in claim 1, whereinsaid bonding strip is attached by heat-sealing.
 9. A package as definedin claim 8, wherein said bonding strip is attached by spot-welding. 10.A package as defined in claim 1, wherein said bonding strip is providedat one end with a protective skirt tab, suitable for folding over theside wall of the last multicell cuvettes in the row, said tab having alength shorter than the overall height of the cuvettes, yet sufficientlylong to cover the optical area of the cuvettes.
 11. The packageaccording to claim 10, wherein a portion of said protective skirt tabfails to have a bonding substance disposed thereon.
 12. A package asdefined in claim 1, wherein the other end of said bonding strip isprovided with a tab part for pulling for separation of said bondingstrip from said multicell cuvettes.
 13. A package as defined in claim 1,wherein said bonding strip is a flexible band.
 14. A package as definedin claim 1, wherein said bonding strip is attached by ultrasonicwelding.